Subj : DAY1SVR: Day 1 Convective Outlook To : wx-storm@lists.illinois.edu From : COD Weather Processor Date : Sun May 07 2023 19:55:14 ACUS01 KWNS 071955 SWODY1 SPC AC 071953 Day 1 Convective Outlook NWS Storm Prediction Center Norman OK 0253 PM CDT Sun May 07 2023 Valid 072000Z - 081200Z ....THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS FROM EASTERN NEBRASKA AND KANSAS INTO IOWA...NORTHERN MISSOURI...AND FAR NORTHWEST ILLINOIS... ....THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM THE CENTRAL PLAINS INTO THE MID MISSISSIPPI VALLEY...AND OVER PARTS OF WEST TEXAS... ....SUMMARY... Scattered severe thunderstorms are most likely across parts of the central Great Plains to the Mid-Mississippi Valley from late this afternoon through tonight. Very large hail, destructive wind gusts, and a few tornadoes will be possible. Little change was needed for the 20Z update. The corridor from NE across IA and IL continues to destabilize, beneath moderate mid/high level westerlies and near a surface boundary. The main severe threat will develop later this afternoon and persist through the evening when a southerly low-level jet from KS into MO noses into IA. Otherwise, diurnally driven hail and wind is expected over parts of western and northwestern TX later today, with scattered severe storms producing strong gusts and sporadic hail from southern IL into much of TN through evening. For more information, see the following mesoscale discussions: Nebraska MCD 705 Iowa MCD 710 Texas MCD 709 Illinois/Tennessee MCD 706 MCD 707 MCD 711 ...Jewell.. 05/07/2023 ..PREV DISCUSSION... /ISSUED 1121 AM CDT Sun May 07 2023/ Morning water vapor loop shows broad southwesterly winds aloft across much of the central US, with several minor shortwave troughs embedded in the flow. Sufficient low-level moisture and instability is present to lead to multiple areas of concern for afternoon strong/severe thunderstorm activity. ....Central Plains... A persistent surface boundary extends from northwest KS eastward into southeast NE. Easterly low-level winds to the north of the boundary is maintaining 50s dewpoints and a corridor of moderate CAPE, along with relatively strong westerly flow aloft. A fast-moving shortwave trough currently near the CO/UT border will track eastward into the Plains by late afternoon, leading to scattered thunderstorm development near the boundary. These storms will likely become severe and move eastward through the evening. Large hail and damaging winds will be possible. ....IA Vicinity... As the UT/CO shortwave trough ejects into the Plains later today, large scale forcing for ascent will spread eastward into the MO Valley. Strengthening low-level winds and convergence along the boundary will lead to intense thunderstorms by late afternoon, spreading eastward across IA and northern MO. Large CAPE values will promote a risk of very large hail and damaging winds with these storms, along with the likelihood of upscale growth during the evening into one or more bowing structures. This activity will move into central IL by late evening. Meanwhile, the activity farther west of NE will move across the same areas after dark. This scenario of multiple rounds of severe storms leads to the 30% hail/wind probabilities and the ENH risk. ....IL/KY/TN... A large linear MCS is sagging southward across much of KY this morning, with a risk of locally strong-damaging wind gusts throughout the day. Strong heating and ample low-level moisture will develop along the western flank of this activity from central IL into western KY/TN. This area is expected to see convective rejuvenation by mid/late afternoon. Forecast soundings show profiles capable of hail and damaging wind gusts, along with a chance of bowing structures during the evening. ....West-Central TX... Relatively clear skies will reside along the dryline across west-central TX and southwest OK today, where a very unstable air mass will develop. Dewpoints in the upper 60s to near 70F will combine with steep mid-level lapse rates and yield MLCAPE values around 4000 J/kg. Similar to yesterday, thunderstorms will develop along the dryline by mid-afternoon and spread slowly eastward. Very large hail and damaging wind gusts will be possible with a few of the storms. ....South TX... Multiple CAM solutions suggest that intense storms over northern Mexico will track across the Rio Grande and into south TX this afternoon and evening. Therefore have extended the SLGT risk for hail and wind into this region. $$ = = = To unsubscribe from WX-STORM and you already have a login, go to https://lists.illinois.edu and use the "Unsubscribe" link. Otherwise email Chris Novy at cnovy@cox.net and ask to be removed from WX-STORM. --- SBBSecho 3.14-Linux * Origin: capitolcityonline.net * Telnet/SSH:2022/HTTP (1:2320/105) .